Trudeau added that the province can look forward to greater inter-governmental co-operation after years of thorny relations between provincial Liberals and the federal Conservatives under Stephen Harper.

“After a decade of indifference and even neglect, Ontario has a dedicated and ambitious partner in Ottawa,” he said.

It’s unusual for a prime minister to wade into a provincial byelection, but Ontario Premier Kathleen Wynne took a high-profile role in Trudeau’s campaign in the recent federal election, which apparently paid off.

The result won’t change the balance of power in the provincial legislature, but could provide a boost for Wynne’s embattled government and also mark a coup for rookie Progressive Conservative Leader Patrick Brown.

Polls are indicating a close race between Roy and Progressive Conservative Lorne Coe.

The Liberals, who held only 13 seats in the province when the federal election was called, were elected in 80 of Ontario’s newly expanded total of 121 seats.